Castoraeschna longfieldae (Kimmins, 1929)

Carvalho, Alcimar L., Souza, Pedro Henrique R. & Calil, Eduardo R., 2006, Description of the larvae of Castoraeschna colorata (Martin, 1908) and C. longfieldae (Kimmins, 1929) (Insecta: Odonata: Aeshnidae), with a key to the known larvae of the genus, Zootaxa 1296, pp. 19-28 : 20-23

Castoraeschna longfieldae (Kimmins, 1929)

( Figures 1–6 )

Material

BRAZIL, MATO GROSSO, Chapada dos Guimarães, Parque Nacional da Chapada dos Guimarães: Cachoeira dos Namorados (found in detritus near the margins of pool), 19.II. 2000, A. L. Carvalho leg., 1 female, emerged 6.III.2000 (final instar larval exuvia); Salgadeira, Rio Independência (first spring), 19.II.2000 [?], A. L. Carvalho leg., 1 male (final instar larva). Material deposited at the entomological collection of the Departamento de Zoologia, Instituto de Biologia, UFRJ, Rio de Janeiro, Brazil.

Description

Body elongate and covered with granules and short setae. General color orangeochraceous, with dark brown and pale ochraceous spots.

Head ( Figs 1–3 ). Pentagonal in dorsal view, with antero­lateral angles rounded, occupied by compound eyes. Labrum and postclypeus yellowish, with a pair of indistinct dark spots at their bases; anteclypeus pale, striated and without setae. Areas corresponding to muscular insertions of occiput glabrous and darkened. Antennae with 7 articles, the third the longest, the first the shortest. Mandibles with the following formula: L 1234 0 ab (k?) / R 1234 y a(m1)bb’ (k?). Labium, when folded, reaching posteriorly anterior border of metathoracic coxae. Prementum slightly concave in dorsal view; its width a little shorter than 3/4 its length; ligula pronounced, with median cleft near middle; a pair of spines on sides of median cleft resembling tubercles, dark and small, shorter than fringe of piliform setae; 2 or 3 short setae on each side of dorsal surface of articulation between ligula and palps. Movable hook about 1.75 times as long as outer margin of first article of labial palps; palpal lamina truncated distally; distal and outer margins forming an angle about 85°; end hook developed with apex sub­acute, slightly oblique in relation to lamina; internal margin and the end hook forming an angle of around 110°; pair of end hooks a little overlapping when palps closed; distal margin with 7 denticles; outer margins, when the palps closed, forming an angle inferior to 10°; internal margin with about 15 to 20 denticles; presence of 6 to 12 irregularly distributed setae at each side of dorsal surface of the region below insertion of movable hook; presence of another group of 6 to 12 smaller setae in the base of the same article; movable hooks with apex acute, bearing a longitudinal row of about 40 to 50 short setae on their dorsal surface.

Thorax. Pronotum little pronounced, with rounded lateral angles; a pair of spots corresponding to areas of muscular attachments evident; prothoracic pleural processes projecting laterally, forming an angle of about 45° in dorsal view; the posterior process distinctly larger than the anterior one. Wing cases parallel; posterior pair reaching distally posterior border of fourth abdominal segment; sub­basal dark spot on costal border evident. Femora with 4 poorly defined dark­brown stripes, more distinct on first pair and less on third; tarsi tri­articulated, with rows of tridentate spines on ventral surface disposed as follows: tarsi of three pairs with 2 parallels rows along articles, confluent on base of first, where simple spines and elongate setae also occur; second article of three pairs of legs with an additional third row between its ventral face and its anterior margin; second article of third pair also with a row between its ventral face and its posterior margin; first article of first pair also with a row between ventral face and anterior margin; tibiae bearing simple and tridentate spines on ventroapical surface, not arranged in a row.

Abdomen ( Figs 4–6 ). More than twice as long as head plus thorax; segment 6 the widest in dorsal and the tallest in lateral views. Color pattern consisting on pairs of dark spots at muscular impressions, at the medio­dorsal and the lateral areas of each segment; dorsal spots arranged as a longitudinal dark stripe on abdomen; a row of denticles present between tergites and intersegmental membranes, but interrupted near lateral muscular impressions. Lateral spines on segments 6 to 9, pale each with dark apexes; lateral spine of segment 7 almost reaching distally the level of posterior margin of adjacent membrane; lateral spine of segment 8 surpassing a little the level of posterior margin of adjacent membrane; lateral spine of segment 9 reaching middle portion of tergite 10. Rows of spines adjacent to sternites and ventral intersegmental membranes limited to lateral areas in all segments, except by a complete row on 9. Female gonapophyses barely surpassing posterior limit of sternite 9; ventral pair slightly longer than lateral ones. Anal appendages ochraceous, with dark acute apexes; subapical region of epiproct and sub­basal region of cerci pale; cerci and epiproct subequal and a little longer than lateral length of abdominal segments 9 plus 10; paraprocts slightly longer than cerci and epiproct; apexes of cerci and paraprocts slightly decurved medially; apex of epiproct flattened and excised in the middle, bordered laterally by sharp spines, parallel in dorsal view and a little shorter than width of appendage; epiproct with weak continuous mediodorsal carina, specially distinct in dorso­lateral view; base of male epiproct with a triangular projection, extending about 1/3 of appendage length; epiproct and paraprocts with long setae concentrated on carinae.

Measurements (mm, for female exuvia and male larva, respectively): total length 53.21 / 50.79; median length of head 7.60 / 6.35; maximum width of head 10.32 / 10.10; length of right antenna 3.12 / 3.36; length of antennomeres 0.33, 0.41, 0.68, 0.39, 0.47, 0.47, 0.37 / 0.33, 0.45, 0.86, 0.33, 0.41, 0.47, 0.51; median length of prementum 8.59 / 8.59; maximum width of prementum 6.02 / 6.09; length of posterior right wing case 11.33 / 10.88; length of posterior right femur 8.51 / 8.70; length of abdomen (including anal appendages) 35.17 / 33.14; maximum width of abdomen (segment 6) 9.77 / 9.18; length of right female gonapophyses (measured from posterior limit of segment 8): lateral (including stylus) 2.64; ventral 2.68; internal 2.75; length of epiproct (lateral view) 4.04 / 4.46; male projection of epiproct 1.81; length of right cercus (lateral view) 4.29 / 4.79; maximum length of right paraproct (lateral view) 4.37 / 5.08.

Figures

FIGURES 1 – 6: Castoraeschna longfieldae, female ultimate instar exuvia (1 – 5): 1 head, dorsal view; 2 left antenna, dorsal view; 3 distal part of prementum and palps, dorsal view; 4 abdominal segments 6 – 10 and anal appendages, dorsal view; 5 abdominal segments 8 – 10 and anal appendages, ventral view; male ultimate instar larva (6): anal appendages, dorsal view.